What specific anatomical feature allows the woolly monkey's tail to function as a fully prehensile fifth limb?

Answer

A bare, tactile pad on the underside near the tip

The prehensile tail is one of the most specialized adaptations of the woolly monkey, essential for its existence high in the trees. Its capability to function as a fifth limb, enabling the monkey to support its entire body weight while reaching for food or navigating gaps, relies specifically on the presence of a bare, tactile pad located on the underside toward the tip. This pad significantly enhances friction and sensitivity, allowing for an incredibly strong and secure grip on branches. Although the tail's overall length contributes to its utility as a counterbalance and anchor, the tactile pad is the critical element providing the necessary grip surface.

What specific anatomical feature allows the woolly monkey's tail to function as a fully prehensile fifth limb?
mammalfactMonkeyPrimate